Amoeba, an UCI compliant open source chess engine by Richard Delorme, written in D language, first released in May 2016 [1], licensed under the GPL v3.0. Amoeba uses the Nelder–Mead method [2] or downhill simplex method [3] to tune its evaluation parameters, also called amoeba method and eponym of the program [4].
Amoeba search of Simionescu function [5]

Features

Board Representation

• Bitboards
• Hyperbola Quintessence and Rank Attacks
• Mailbox
• Staged Move Generation

Search

• Iterative Deepening
• Aspiration Windows (improved in 2.6)
• Principal Variation Search
• Transposition Table (improved in 2.6)
• Quiescence Search
• Internal Iterative Deepening
• Static Exchange Evaluation (SEE pruning improved in 2.6)
• Check Extensions
• Null Move Pruning
• Reverse Futility Pruning
• Razoring
• Mate Distance Pruning
• Late Move Reductions (improved in 2.6)

Evaluation

• Tapered Eval
• Lazy Evaluation
• Mobility
• Pawn Structure
• Tempo
• Automated Tuning using Nelder–Mead method aka Amoeba method

Tournament Manager

• With the release of Amoeba 2.1, the code of a tournament manager was published also written in D language, used to validate or reject Amoeba changes ^[7]. So far only with fixed time per move, it

• can use various openings from pgn file
• can play several games in parallel
• can set H0 & H1 hypothesis for SPRT ^[8]
• can saves played game to a pgn file

See also

• Dumb

Forum Posts

2016

• amoeba a new UCI engine by Richard Delorme, CCC, May 20, 2016
• Amoeba 1.3 released by Richard Delorme, CCC, August 03, 2016
• Amoeba 2.0 by Richard Delorme, CCC, November 27, 2016

2017

• amoeba 2.1 by Richard Delorme, CCC, January 24, 2017
• sprt tourney manager by Richard Delorme, CCC, January 24, 2017 » Amoeba Tournament Manager, SPRT
• amoeba 2.2 released by Günther Simon, CCC, March 03, 2017
• Amoeba 2.4 by Richard Delorme, CCC, April 19, 2017
• Amoeba 2.5 by Richard Delorme, CCC, June 07, 2017
• Amoeba 2.6 by Richard Delorme, CCC, September 22, 2017
• Amoeba 2.7 by Richard Delorme, CCC, December 11, 2017

2018

• Amoeba 2.8 by Richard Delorme, CCC, March 18, 2018

External Links

Chess Engine

• GitHub - abulmo/amoeba: an UCI chess engine in d language
• Amoeba in CCRL 40/40

Misc

• Amoeba from Wikipedia
• amoeba - Wiktionary
• Amoeba (genus) from Wikipedia
• Amoeba (disambiguation) from Wikipedia
• Amoeba (mathematics) from Wikipedia

References

1. ^ amoeba a new UCI engine by Richard Delorme, CCC, May 20, 2016
2. ^ John Nelder, Roger Mead (1965). A Simplex Method for Function Minimization. The Computer Journal, Vol. 7, No. 4, doi:10.1093/comjnl/7.4.308
3. ^ Margaret H. Wright (2012). Nelder, Mead, and the Other Simplex Method. Documenta Mathematica, Extra Volume Optimization Stories, pdf
4. ^ amoeba/README.md at master · abulmo/amoeba · GitHub
5. ^ Animated Nelder-Mead minimum search of Simionescu function, by Pasimi, November 22, 2016, CC BY-SA 4.0, Wikimedia Commons
6. ^ Features as mentioned in amoeba/README.md at master · abulmo/amoeba · GitHub
7. ^ sprt tourney manager by Richard Delorme, CCC, January 24, 2017
8. ^ The SPRT without draw model, elo model or whatever... by Michel Van den Bergh, CCC, September 01, 2015

What links here?